I joined September 12, 2009. I actually joined because on that day Pokemon SS/HG (Japanese) and Mario and Luigi Bower's Inside Story were all dumped. They also all came with some extremely strong AP, which caused a huge uproar. Everyone was joining and viewing the site, threads were flooding the forums asking "IS THER AN R4 PACH ET?" people wanted English patches for the Pokemon games (even though there wasn't even an AP patch.)
Members these days don't know what a real flood looks like. They think a few threads is a "flood," imagine hundreds, if not thousands of threads being made about a game. Imagine having so many people joining/viewing the site that it actually caused crashes in the forums. Imagine Black Friday expect worse. It was a mess, so the staff shutdown the site to guests and required everyone to join if they wanted to see the forums. So I created a throwaway account to complain that my games weren't working.
Then I ended up staying because the M3 forums.